Unless the Intel chipset run a lot hotter than any AMD motherboards I've owned that is cooking hot.
My AMD chipset is currently idling at 25C and the temp warning is set to 40C, but previous motherboards have run between 40-45C under load on hot days (30+C).

Is the PC shutting down or running unstable ? If not the temp sensor may be going crazy.

If the temp is correct and as the temps are good on the rest of the components, and the chipset has passive cooling (no broken fan to replace),
unless there is something completely blocking the chipsets heat-sink, it's looking to me like you are may have to RMA the motherboard.